Polymers having halogen cure sites are well known. Examples of these are polychloroprene rubbers, the epihalohydrin elastomers, the chlorine cure site acrylate rubbers, and bromobutyl rubbers. These polymers react with curing agents at the halogen cure site to yield vulcanized elastomers of established utility. Art on curing of halogen-containing polymers relevant to the present invention is as follows: U.S. Pat. Nos. 2,600,414; 3,488,331; 3,686,156; 3,732,174; and 3,732,190. Polymers having carboxyl cure sites are also well known. Examples of such are the carboxyl cure site acrylate rubbers and the polyacrylic acids. These polymers react with curing agents at the carboxyl cure site to yield useful vulcanizates. Art on curing carboxyl-containing polymers relevant to the present invention is as follows: U.S. Pat. Nos. 2,604,668; 2,649,439; 2,669,550; 2,724,707; 2,726,230; and 3,404,134.
The two types of polymers can be physically admixed to provide polymer blends. However, the polymer blends have limited utility unless a satisfactory method of co-curing the polymers in the blend is devised. The most beneficial and efficient method is to use a cure system that promotes co-curing of the polymers.